Facial Soft Tissue Thickness In Caucasian Children With Different Skeletal Classes And Soft Tissue Profile: A Retrospective Study

Abstract

Background: Facial soft tissue influences orthodontic treatment and is essential for facial reconstruction in forensics. Its position is determined by the underlying hard tissue. Facial soft tissue thickness of midline components is conventionally measured using a two-dimensional (2D) lateral cephalometric radiograph.

Aim: This retrospective three-dimensional (3D) cone beam computed tomography (CBCT) imaging study investigates and compares midline and bilateral facial soft tissue thickness (FSTT) in patients with different skeletal Classes and soft tissue profiles.

Materials and Methods: Following Institutional Review Board (IRB) approval, a convenient sample of CBCT images was obtained for 55 Caucasian subjects (28 males and 27 females) with the mean age of 11.1 years (SD: ± 1.99 years). Two cephalometric measurements and twenty-two facial soft tissue thickness (FSTT) parameters were selected and measured. The sample was divided into three skeletal Classes and soft tissue profile groups based on the ANB angle measurement: Class I (ANB ≤ 3.5° and ≥ 1.5°), Class II (ANB ˃ 3.5°) and Class III (ANB < 1.5°). The intraclass correlation coefficient (ICC) was measured to assess the intraobserver reliability ≥ 0.9. ANOVA test was used to compare the means of the selected parameters and P-value ≤ 0.05 was considered significant in all statistical analyses.

Results: In Class I group, the correlation coefficient between ANB angle and FSTT parameters showed statistically significant differences for points: Glabella, Nasion, right midsupraorbital, left mid-supraorbital, right posterior anterior ramus, left posterior anterior ramus, iii right Gonion, and left Gonion. The correlation coefficient between the soft tissue profile and all FSTT showed statistically significant differences for point B and Pogonion point. In Class II group, the correlation coefficient between soft tissue profile and all FSTT parameters showed statistically significant differences for points: B, Pogonion, right zygomaticofrontal medial suture, and left zygomaticofrontal medial suture.

Conclusion: Differences of soft tissue depth between skeletal Classes and soft tissue profile were observed. Most of the statistically significant differences were found in skeletal Class I group, while skeletal Class II group showed less statistically significant differences.